How to use the Text Diff Checker
- Paste the old version into "Original" and the new version into "Changed".
- Optionally turn on "Ignore whitespace", "Ignore case" or "Only changes".
- Differences appear below: green + for additions, red − for deletions, with original and changed line numbers.
- Press "Download" for a .diff file or "Copy" to copy the changes.
Examples
Compare a config change
Original:
port=80
host=localhost
debug=true
Changed:
port=443
host=localhost
-port=80
+port=443
host=localhost
-debug=true
Specs & key facts
| Granularity | Line by line (longest common subsequence algorithm) |
|---|---|
| Options | Ignore whitespace, ignore case, only show changes |
| Export | Unified diff (.diff) |
| Recommended size | Up to a few thousand lines per side |
| Processing | In your browser (nothing is uploaded) |
| Price | Free, no sign-up |
FAQ
Can I compare Word or PDF files?
Copy the document text and paste it as plain text. The tool compares text, not fonts or formatting.
Why is a whole line shown as removed and added when I changed one word?
The comparison works per line, so any change within a line shows the old line as removed and the new line as added.
What does "Ignore whitespace" ignore?
It treats runs of whitespace as one space and ignores leading and trailing whitespace — useful for code with different indentation.
Is my text stored?
No. The comparison runs in your browser and nothing is uploaded.